Spark plug



S. P. PIETSZAK.

SPARK PLUG.

.AJFLICATiON FILED JAN. I. H2L

1,416,868, Patented May 23, 1922.

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trode being so related and interconnectedv UNITED.STATES,;f;PArftmvof y army 1?, rmrszam or* numana,

suitable terminals areformied for the-passage of aV spark across a'gap vtherelxetweenij The primary object of the resent invenf tion is to provide a spark p ug forr'ned'j'ina number of durable and' efficiently associ-1 ated arts' wherebyr anyI onegof said-parts,A

vrenewed from time to' time-when found necessaryso as'to vovercome the present waste and'expense duel to the fact thatthe spark plugs now in use, most always have i to be entirely. discardedfwhendamaged 'in J many ways.

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The invention consists broadly in ya spark therefor in the gas engine cylinder, and carrying an'insulator formed in two transverse" sections, the lower one-of whlch is arranged to removably "carry in a practical'manner the lower section of the'central electrode', and the upper one of which is adapted to. similarly carry the upper section of said electrode, and the two sections ofthe elecas to insure effective operation.

With the above and other objects in view,

the present invention consists in the novel form, combination and arrangement of parts hereinaftermore fully described and shown in the accompanying drawings, in which like reference characters designate corresponding parts throughout' the several views.

In thedrawings, A

Figure l is an elevational view of the assembled plug and` shown in the cylinder opening of an internal combustion en ine, only a fragment of the latter being ilustrated,

Figure 2 is a substantially central verti-l fployed at 1 the binding Y 3` is an elevational'view- 'of the upper'zsection of the centralelectrode,

ig'ure 4' is a similarVv view ofthe lower.:

section of saidv electrode,` v v iFigure 1s a, lan'vview of a. washer ein-- upper electrode section. i

. VFig'u're 6 is a plan view' of one vof the `soft metal washe'rseemployed between the, insula to'r' and the`.'casing to insurevagai'nst leakage between these parts, A =f .1 Figure f( is a similar view of an insulat- -ingwaeherj` employed between the twofsections vof the insulator,

which-is carried by. the lower insulator secst portion of the Figure 8 .isf'a similar` view of the'nut c tionfor threadedengagementl with the lower e Y electrode'section whereby the latter is held 'l in lace,

washer employedbelow" the nut of Figure -8 to act as a guide lfor thelower electroesee# `tion forpreventing damage to the lower in-V plug having the usual metallic icasirigefor'v being "threaded into the opening. provided' sulatorsection, and u u Figure 10 is anv elevational view of the i mall renewable electrode. ihaving detachv able connection with 'the casing of the spark,

vrReferringmore in detail to the several.4

views, the present invention includes thel tened upon the body 5 at the upper end of the threads 6 thereof so as to form an abutthreaded as at 6 y at its lgine cy inder 7. A washer 8 is suitably fasment for limiting the inward movement of the plug into thecylinder 7 and for insuring a tight fit at this point for preventing leakage, the washer 8 being formed of relatively soft material .such as lead for facilitating it 1n performing this function.

At the lower end of the shell or casing 5, there is provided as usual the small electrode 10 which is preferably L-shaped as shown, and the free end of this electrode is adapted to form a spark point. The upper end portion of the electrode 10 is threaded as at 11 so as to be detachably received in a i socket provided therefor in the shell 5 as clearly shown in Figure 2. An angular portion or enlargement 12 is provided at the base of the threaded portion 11 of the electrode 10 so as to form a stop and adapted to be engaged by a small wrench or the like for threading the same into place Whenever renewal of this electrode is found necessary. The shell 5 is provided with a bore 13 having a shouldered portion 14 about midway between the ends and above which the bore is of greater diameter, suitable threads being provided as at 15 within this larger diametered portion of the bore. To cooperate with the threads 15, the threaded locking nut 16 is employed, and it may be hexagonal or of other angular form so that it may be engaged by a wrench when desired for removal pur oses or the like.

Dispose within the shell 5, there is an insulator, which in the present illustration,

is shown as being formed in two parts indicated by 17 and 18. The part or section 17 is provided with a longitudinal bore 19 and in its lower end it is provided'with an enlargement 20 of the bore for engagement with the head 21 of the upper electrode section 22 for preventing the latter from being withdrawn through the insulator section in one direction. A soft metal washer 23 is placed between the lower edge of the nut 16 and a shoulder provided by the flange 24; on the lower end of the insulator section 17, for lthe purpose of providing a packing at this point to insure against leakage of the gases between the shell 5 and the insulator, A washer 25 is positioned upon Athe upper end of the insulator section 17 so as to guide the upper electrode section 22 and thereby protect said upper electrode insulator section 17 against damage from vibration of the metal member 22 thereagainst. A split spring washer of the usual kind and indicated at 26 is superimposed upon the washer 25 and these two washers 25 and^`26 are tightly jammed against the upper end of the insulator section 17 by 'a nut 27. The nut 27 is threaded upon the threaded portion 28 of the upper electrode section 22 and the wire of the ignition circuit is adapted to be fastened between this nut 27 and the usual knurled nut 28 in the usual manner.

The other or lower insulator section 18 is provided with a flat upper surface similaito that of the upper and lower surfaces of the upper electrode' section 17, and the upper end ot' the section 18 is also flanged as at 29.

' Another soft metal washer 23 is placed between the shoulder 14 of the casing 5 and the adjacent shoulder of the flange 29 of the lower insulator section 18 so as to avoid leakage at this point between the lower section 18 and the casing 5. The lower ortion of the insulator section 18 is in the orm of a tubular apron having a longitudinal bore bore 19, viz, movement of the electrode section 33 into the insulator section 18 is limited by this formation of parts. A protecting and insulating washer 34 is placed between the adjacent ends of the insulator sections 17 and 18, and this washer 34 may be of fibre or the like so as to prevent possibility of the current passing directly from the metallic parts such as the head 20 to the shell 5. The lower electrode section 33 is provided with a reduced extension 35 which extends to a point in slight spaced relation to the free end of the electrode 10, whereby the usual spark gap is provided.

is enlarged at its upper end as shown in Figure 2 to provide an internal shoulder as at 36, and a washer 37 rests upon this internal shoulder, said washer 37 being provided with an opening of such diameter as to guide the lower electrode section 33 without contacting the walls of the bore 30, thereby guarding against damage to the lower insulator section 18. A nut 38 rests upon the washer 37 within the enlarged portion ot the bore 30, and the threaded upper portion 39 of'- the lower electrode section 33 is threaded into the nut 38 whereby it is held in place. The head 21 of the upper electrode The bore 30 of the lower insulator sectionv section 22 is provided with an angular socket 40, and the upper end'of the lower electrode section 33 is provided with a reduced angular lug or extension 41 which snugly fits within -the socket 40. In assembling the parts, the upper electrode section 22 is allowed to remain loose while the lower electrode section 33 is threaded into place. The electrode section 22 is then lowered for permitting the extension 41 to enter its socket 40, and the nut 16 is then threaded inwardly to clamp the parts in place.

It will be seen from the several points of `construction that a very eflicient spark plug is thus provided which may meet 'with all of thev requirements for a successful commer-l cial use and the various parts of which may be sold separately and kept in stock so that the users of these plugs may renew the various parts from time to time as found necessary without discarding the entire plug as is now generally done.

Minor changes may be made without departing from the spirit and scope of the invention as claimed. Y

What is claimed as new is:

A spark plug of the class described comprising a metallic shell, an upper and lower insulator section having a longitudinal bore, the lower end portions of the longitudinal bore in each Section being outwardly tapered deining a. socket in the ends of said insulator sections, an upper and lower electrode section being outwardly tapered at their 5 lower ends for-reception in the said sockets of the insulator sections, an angular lug upon the upper end ojfthe lower electrode fitting within a socket in the enlarged lower end of the upper electrode, means for retaining 'tlie electrodes in the insulator seotions and means for looking the insulator sections Within the metallic shell.

In testimony whereof I affix my signature.

STANLY P. PIETSZAK. 

